Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare safety traits (readOnly, idempotent, non-destructive, closed world), so the description's job is to add operational context. It does so richly: it details the exact event taxonomy returned, notes each event carries an exact time, constrains the date range to 1–31 days, and links to a full output/error contract. Little behavioral information is missing for an agent deciding how to use it.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose, then cleanly separated into WORKFLOW, INPUT CONTRACT, and DO NOT CONFUSE WITH sections. Every sentence contributes either scope, usage routing, or parameter clarification, and the URL is terse. It is long but earns its length given the tool's complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present and annotations covering safety, the description only needs to cover selection, scoping, and workflow. It does all three completely: it distinguishes the tool from related siblings, states the date-range constraint, and provides before/after workflow steps. Nothing an agent needs to invoke it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents every parameter's meaning, format, and default. The description largely repeats that information ('from_date ... defaults to today', 'days 1-31 default 7') without adding syntax, constraints, or interaction rules beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific resource—a timeline of astrological events for a chart over 1–31 days—and enumerates the exact event types it returns (aspects, ingresses, stations, Moon changes, eclipses, profections). It distinguishes itself from siblings by explicitly naming what it is not ('timeline of exact moments' vs. day snapshots).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit workflow guidance with a BEFORE tool (asterwise_get_western_natal) and an AFTER tool (asterwise_get_western_daily_factors), plus a 'DO NOT CONFUSE WITH' section that names the closest alternative (asterwise_get_western_transits_monthly) and explains the difference. This removes guesswork.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.